81970569216 has 560 divisors, whose sum is σ = 263762630208. Its totient is φ = 25303449600.

The previous prime is 81970569211. The next prime is 81970569217. The reversal of 81970569216 is 61296507918.

81970569216 is a `hidden beast` number, since 8 + 1 + 9 + 70 + 569 + 2 + 1 + 6 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81970569211) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 625729471 + ... + 625729601.

Almost surely, 2^81970569216 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81970569216, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (131881315104).

81970569216 is an abundant number, since it is smaller than the sum of its proper divisors (181792060992).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81970569216 is a wasteful number, since it uses less digits than its factorization.

81970569216 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 233 (or 200 counting only the distinct ones).

The product of its (nonzero) digits is 1632960, while the sum is 54.

The spelling of 81970569216 in words is "eighty-one billion, nine hundred seventy million, five hundred sixty-nine thousand, two hundred sixteen".